What's "copper interleave" - the only references I can find on Google are this thread, and another post by you regarding Atari ST emulation on the Amiga
Ah. Clarification. On the Amiga, bitplanes are ordered consecutively (i.e. it's like multiple monochrome bitmaps layered on top of each other).
On the ST, they're interleaved (1 word from plane 0, followed by 1 word from plane 1, by one word from plane 2, one word from plane 3, one word form plane 0 ... etc).
Using the copper, it's possible to create something similar: 1 longword for plane 0, 1 longword for plane 1, 1 longword for plane 2, 1 longword for plane 3 etc. I suspect that it's fairly useless to do so however, and hence it's possible that the term "copper interleave" isn't very common at all.
Note: Word in this case is 16 bits, longword is 32 bits.